Security lock



2 Sheets-Sheet 1 May '22 w34 E. scHMm-r SECURITY LOCK Filed sept. 17.1952 2 sheets-sheen 2 INVENTQR DMD SCM/wim Patented May 22, 1934 UNITEDSTATES PATENT OFFICE 2 Claims.

This invention relates to locks and more particularly to locks of thelever tumbler type adapted for doors and like objects whereby they maybe securely held when in closed position.

One of the objects of the invention is to provide a lock which can beoperated from both sides by a key having two diierent kinds of bits onthe same stem.

A further feature is in the provision of means within the lock casingwhich prevents opening oi the lock with a false key.

Another purpose is to produce a lock operable from one side by a keyincapable of operating from the other side.

These important purposes are accomplished by the novel construction andcombination of parts hereinafter described and illustrated in theaccompanying drawings, constituting a material component of thisdisclosure, and in which:

Figure 1 is a side elevational view of an embodiment of the invention,the cover plate being omitted.

Figure 2 is a similar view from the opposite side of the lock.

Figure 3 is a side elevational View of a specic form of the key used inconnection with the lock.

Figure 4 is a transverse sectional View taken on line 4 4 of Fig. 3.

Figure 5 is a similar sectional View taken on line 5 5 of Fig. 3.

Figure 6 is an enlarged transverse sectional view of the lock taken online 6 6 of Fig. 1.

Fi/gure 7 is a longitudinal sectional View taken on line 7 7 of Fig. 1.

Figure 8 is a fragmentary sectional view oi the lock casing showing thebolt in a retracted position, the section being taken on line 8 8 ofFig. 6.

Figure 9 is a similar View taken on line 9 9 of Fig. 6, showing theopposite side of the bolt.

Figure 10 is another like View looking on line 10-10 of Fig. 6.

Figure 11 is a View similar to Fig. 9, but showing the bolt in anoutward position.

Referring in greater detail to the drawings the lock casing is shown tobe comprised of a back plate 15, generally rectangular in profile.

A face plate 17 connects between side walls 18 l9 integral with arear-wall 20, these walls being of materially lesser height than theface 17.

A cover plate 21 completely covers the walls 18-19 and is secured byscrews in the usual manner to studs projecting inwardly from the plate15.

A bolt 22, slidable in the casing to be projected through an opening inthe face plate 17 is provided with a ledge 23 limiting its outwardmovement by contact with the plate.

The shank of the bolt contains a central longitudinal recess 24 in whichoperates a pivoted plate 25 pivoted on a stud 26 set in upper and lowerelements respectively 27 28 of the shank, and through which are formedlongitudinal registering slots, 29-30.

A rectangular stud 31, fixed in the back plate 15, engages the sideedges of the slots to act as a guide for the bolt, and also extendsupwardly through the cover plate 21.

The stud 31 also passes through a corresponding slot 32 in the pivotedplate 25, this latter slot being straight at its rear edge which ismaintained normally against the stud by a flat spring 52 iiXed in plate25, which is further provided with three spaced notches 33-34 35 in itsfront edge, these notches being curved with a radius struck from thestud 26, permitting the plate 25 to swing in the manner indicated inFigs. l0 and Plugs 36 are fixed in pivoted plate 25 to extend 'equallythrough both sides, to maintain the pivoted plate centrally of the boltshank elements 27 28 and tend to prevent sticking by contact of thesuperiicial areas.

In the rear edge of the shank element 27 are three notches 37 38 39, andin the mating element 28, are similar notches, 37 38 39, allcorresponding in distances apart to the wing notches 33 34-35.

Engageable in the notches of the lower bolt shank element 28 is thehooked end of a tumbler 40, its opposite end being looped around a post41 Xed in the front portion of the casing, the turnbler being pressedinto engaging position by a flat spring 42 coiled about a rectangularstud 43 iiXed in the casing, see Fig. l.

In a similar manner an opposed tumbler 44 has a hooked end to engage thenotches 37 38 39 in the shank element 27, the opposite end of thetumbler being looped around a post 45 xed in the rear portion of thecasing and pressed into engagement by a iiat spring 46 coiled about asquare stud 47 ixed in the casing.

Carried by the tumbler 40 is an inreaching flat plate 48, disposedbetweenvthe lower surface of the shank element 27 and casing back plate15, and having a cam-like opening 49.

A similar flat plate 50 is carried in a like manner by the tumbler 44 tobe disposed between the upper surface of the shank element 27 and underside of the partial cover plate 2l, the

`to the tumbler plate 48, spring 42 plate 50 having an ellipticalcam-like opening 51.

The width of the bolt shank element 28 is materially less than that ofthe mating element 27 and formed in its edge, opposite the notches37-38'-39' are ward recesses 55-56 having angularly bevelled entrances.

Similar ward recesses 57-58 are formed in the corresponding edge of theupper element 27, these recesses registering longitudinally of the boltbut are not in lateral registration due to the different widths of theshank elements and serve a purpose later n apparent.

Formed in the back plate is a key hole 60 having a circular portion 61from which leads a slot 62 having two lateral notches 63-64 on one sideand three lateral notches 65-66-67 on the other, the foot of the keyhole being arcuate.

A similar key hole 76 is formed in the partial cover plate 2l, inregister with the key hole 60, as may be seen in Figs. 1 and 2.

Set rigidly in the plate 2l is a key guide 68 open at 69 to admitpassage of the bits of the key by which the lock is controlled.

This key, shown in Figs. 3, 4 and 5, consists of a round shank 72,preferably having a knurled central portion, the shank being uniform indiameter and provided with ornamental rounded ends 73-74.

Adjacent to the end 73 are two spaced bits 75-76 respectively outer andinner, the outer bit 75 being in excess or the length of the inner bit.On the bit 76 is a single ward 77 midway its length adapted to passthrough the recess 67 of the key hole 60, and opposed end wards 78-79 topass the recesses 63-66.

A space C separates the bit 76 from the outer bit 75, which latter isprovided with a single ward 81, registering with the ward 77 and twoouter opposed wards 82-83 to pass the recesses 64-65.

At the opposite end portion of the key are two similar bits 7576 havinga space 80 therebetween and arranged in a reversed position relative tothe shank 72.

it will now be understood that one end of the key is used from the innerside of the lock, through the key hole 60 and the other end through thekey hole as directed by the guide 68.

In operation, the bolt being in a retracted position, as shown in Figs.8, 9 and l0, and it being desired to move the bolt into a lockedposition from the inner side, as represented by the key hole 60, the keyend 74 is inserted and given the usual partial rotary movement.

The bit presses the tumbler plate 50 outwardly, against the spring 46,removing the turnbler a4 from the bolt notch 37; coincidently the bit 76acts in a similar manner with respect and tumbler 40, releasing it tromthe bolt notch 37', thus freeing the bolt.

rThe bit 75', during turning the key, engages the bolt recess 57, whilethe bit 76' engages the corresponding bolt recess 55, thereby urging thebolt outwardly.

t will be apparent that the lock may be operated irom the other side byreversing the key and inserting it into the lock through the guide 68,whereupon the bolt may be actuated a similar manner.

The use of a spurious key is prevented by the pivoted plate 25, which ismoved outwardly, engages the xed post 3l in any of its several recesses,preventing movement of the bolt, while, due to the spaces fio- 662 aproper key may be used without causing movement or the plate 25.

When the bolt has been fully extended the same is positively held byre-engagement of the tumblers in the bolt shank notches. requiring theuse of a proper key to unlock as well as to lock the device.

Thus it is apparent that normally the bolt bar is held against movementin the case by both of the master tumblers 48 and 50 and the anti-picktumbler 25 is in inoperative position. It is also apparent that anyinstrument or key inserted into the lock from either side and somanipulated as to displace the anti-pick tumbler 25 will positivelyprevent the bolt bar being moved in the case even though the operatorhas succeeded in releasing the tumblers 48 and 56 from the bolt bar andengaging the bar.

As changes of construction could be made within the scope of the claims,is intended that all matter contained in the 'foregoing description orshown in the accompanying drawings shall be interpreted as illustrativeand not in a limiting sense.

Having thus described the invention, what is claimed as new and desiredto secure by Letters Patent, is:-

l. in a lock of the character described, a case, a bolt bar movabletherein and having a plurality of key-engageable portions spaceddiiierent distances from the longitudinal center line oi the bolt bar,whereby a certain key bit arrangement nts said key-engageable portionswhen presented irom one side oi the bolt bar and a reverse key bitarrangement ts said key-engageable portions when presented from theopposite side of the boit bar.

2. In a lock of the character described, a bolt bar having a shankincluding'two laterally spaced wall portions or unequal width, the edgeof one wall portion being disposed outwardly of the corresponding edgeof the other wall portion, and each having key-engageable shoulders atsaid edges, said wall portions at their other edges having tumblernotches, tumblersY engageable with said walls at said notches, ananti-pick tumbler disposed between said wall portions, pivoted on thebolt bar and having an edge disposed outwardly 0f the base of saidkey-engaging shoulders, a post secured to the case positioned to beengaged by the anti-pick tumbler, when depressed between said wallportions, to lock the bolt bar against movement, and said bolt bar beingmovable by means of a key adapted to be inserted into the case andhaving bits adapted to depress the master tumblers to release the boltbar and t0 engage the key-engageable shoulders to move the bolt bar, andhaving a recess adapted to receive the anti-pick tumbler to avoiddisplacing the anti-pick tumbler to lock the bolt bar when the key ismanipulated in the case.

EDUARD SCHMIDT.

